The present invention relates to devices, such as portable telephones, which have an input manipulation portion on the surface of a casing, and more particularly to an input device providing an input manipulation portion.
Already known are cellular phones, i.e., portable telephones, comprising a liquid-crystal display and a touch panel which are provided in combination on the surface of a casing. The display is adapted to present data thereon, while the touch panel enables the user to input data.
For example, FIG. 6 shows a portable telephone having a casing which comprises a front case 11 and rear case (not shown). Provided inside the casing is a circuit board 7 which has a liquid-crystal display 6 mounted on its upper surface. The display 6 has a rectangular screen and a frame 61 surrounding the screen, and is fixedly mounted on the circuit board 7.
The front case 11 has a rectangular first opening 16 corresponding to a large rectangular region included in the screen of the display 6 and positioned toward the head side of the casing, and a rectangular second opening 17 corresponding to the remainder of the display screen, i.e., a relatively small rectangular region thereof. The front case 11 therefore has a slender bar portion 14 formed between the first opening 16 and the second opening 17.
A front panel 2 forming a portion of the front case 11 has a rectangular screen portion 21 corresponding to the first opening 16 of the front case 11, a rectangular window 22 corresponding to the second opening 17 of the front case 11, and a slender bar portion 23 formed between the screen portion 21 and the window 22 and to be lapped over the bar portion 14 of the front case 11. A touch panel 3 is held between the inner peripheral edge of the front panel 2 which defines its window 22 and the inner peripheral edge of the front case 11 which defines the second opening 17 thereof.
Disposed between the liquid-crystal display 6 on the circuit board 7 and the front case 11 is a transparent back plate 5 to be in intimate contact with the rear surface of the touch panel 3. The back plate 5 is in the form of a rectangular body shaped in conformity with the contour of the touch panel 3 and provided with a pair of lugs 51, 51. The back plate 5 is attached to the rear side of the front case 11 by the engagement of these lugs 51, 51 with the rear side of the casing 1.
FIG. 5 shows the display portion and the touch manipulation portion of the portable telephone in section in greater detail. The back plate 5 is attached to the front case 11 by the engagement of the pair of lugs 51, 51 with a pair of hooks 19, 19 formed on the front case 11. The front case 11 has a panel affixing portion 18 formed around the second opening 17, and the outer peripheral portion of the touch panel 3 has its rear surface adhered to the surface of the affixing portion 18 with a double-faced adhesive tape 83. The front panel 2 is provided over the first opening 16 and the second opening 17 of the front case 11, and the inner peripheral portion thereof defining the window 22 and the outer peripheral part of the screen portion 21 are adhered to the surfaces of the touch panel 3 and the front case 11 with a double-faced adhesive tape 84.
With the portable telephone described, the image of a manual key is presented on the screen of the liquid-crystal display 6 in the casing for the touch panel to detect the depression of the key image for inputting data. Accordingly, if the display 6 shows a plurality of key images selectively upon a change-over, an increased number of functions can be realized by key manipulation.
With the telephone shown in FIGS. 5 and 6, however, it is necessary to attach the back plate 5 to the front case 11 from the rear side thereof and to attach the touch panel 3 and the front panel 2 to the front case 11 from the front side thereof. Thus, the telephone has the problem of necessitating a complex procedure because the parts need to be joined to the front case 11 from two directions.
Further when the touch panel 3 is depressed for inputting data, the downward pressure is received by the back plate 5, which is merely engaged with the hooks 19, 19 of the front case 11 and therefore fails to fully receive the pressure. Consequently, the touch panel 3 is forced down by the downward pressure and likely to peel off the double-faced adhesive tape 84 adhering the rear surface of the front panel 2 to the front surface of the touch panel 3. This entails the problem of forming a clearance between the front panel 2 and the touch panel 3 and permitting dust to ingress into and remain in the clearance.
An object of the present invention is to provide a portable input device which can be assembled easily, and is usable for inputting data without the likelihood of dust and the like ingressing into the device.
The present invention provides a portable input device which comprises a casing 1 having a display 6 disposed therein. The casing 1 is provided with a touch panel 3 at least partially covering a screen of the display 6 and is formed in a surface thereof with a panel receiving recessed portion 24 having the touch panel 3 accommodated therein. The recessed portion 24 has a transparent part opposed to the screen of the display 6. The surface of the casing 1 is provided with an exterior sheet 4 covering the touch panel 3 accommodated in the recessed portion 24. The exterior sheet 4 has a transparent portion opposed to a manipulation surface of the touch panel 3, and an outer peripheral portion which has its rear surface adhered to a surface of a panel affixing portion 27 formed around the recessed portion 24.
The portable input device of the present invention can be assembled by fitting the touch panel 3 and the exterior sheet 4 successively into the recessed portion 24 formed in the casing 1 from the front surface side of the casing 1, so that these components can be joined to the casing 1 in only one direction, hence a simplified procedure.
Further when the touch panel 3 is depressed by pressing the surface of the exterior sheet 4 to input data, the downward pressure is reliably received by the panel receiving recessed portion 24 to result in only a slight depression. Moreover, since the outer peripheral portion of the exterior sheet 4 covering the surface of the touch panel 3 has its rear surface adhered to the surface of the panel affixing portion 27 formed around the recessed portion, the downward pressure on the touch panel 3 is unlikely to act in a direction to separate the adhesive joint. This eliminates the likelihood that the exterior sheet 4 will become separated from the casing 1 at the joint, consequently precluding dust and the like from ingressing into the separation.
Stated more specifically, the recessed portion 24 is formed integrally with a front panel 2 made of resin and providing a portion of the casing 1. This gives the recessed portion 24 a high structural strength to reliably receive the downward pressure on the touch panel 3, also ensuring high liquid-tightness.
Further stated more specifically, the recessed portion 24 has a plurality of pins 26 projecting upward from a bottom wall thereof and extending through respective circular holes 32 formed in an outer peripheral portion of the touch panel 3. The touch panel 3 can then be fitted into the recessed portion 24 easily with high accuracy for assembly.
Further stated more specifically, the outer peripheral portion of the exterior sheet 4 is held raised by upper ends of the pins 26. With this construction, the state of contact between the touch panel 3 and the exterior sheet 4 can be adjusted according to the height of the pins 26, whereby the sensitivity of the touch panel 3 to the depression can be determined optimally.
Thus, the portable input device of the present invention can be assembled easily, and is usable for inputting data without permitting the ingress of dust and the like.